1. Field of the Invention
This invention relates to an LED circuit module, especially to an LED circuit module for an LED light tube.
2. Description of Related Art
FIG. 5 shows a conventional fluorescent tube 40, wherein the fluorescent tube 40 has two opposite ends; each end has a first electrode 41 and a second electrode 42. A filament 43 is connected between the first electrode 41 and the second electrode 42. The fluorescent tube 40 has noble gas and mercury (Hg) vapor inside, and fluorescence glue is spread on the internal surface of the fluorescent tube 40.
A conventional lamp-holder of the fluorescent tube 40 has a starter 51 and a ballast 52. When the fluorescent tube 40 is installed in the lamp-holder, the starter 51 is electrically connected to both of the first electrodes 41 of the two ends of the fluorescent tube 40. Both of the second electrodes 42 of the two ends of the fluorescent tube 40 are connected to a mains power (Vac), wherein the ballast 52 is connected between the mains power (Vac) and one of the second electrodes 42.
After power is provided from the mains power, a switch 50 of the starter 51 is closed. The mains power (Vac) through the filament 43 generates a high temperature for performing an ionization of the noble gas in the fluorescence tube. During the ionization of the noble gas, electrons and the mercury (Hg) vapor are generated to react with ultraviolet light. A visible light is generated after the fluorescence glue absorbs the ultraviolet light in the fluorescent tube. The visible light can be applied to general lighting. The ballast 52 is for stabilizing a current flowing through the fluorescent tube.
The fluorescent tube contains a great deal of mercury (Hg) vapor. If broken fluorescent tubes are not recycled appropriately, the mercury (Hg) vapor will evaporate into the air and cause pollution. With the pollution issue from the fluorescent tubes taken into concerns, using light emitting diodes (LEDs) can reduce pollution of the environment.